The present invention relates generally to structures for housing a workpiece during curing and associated methods and, more particularly, to relatively inexpensive structures that facilitate the curing of workpieces on the shop floor or the like and, in some embodiments, are portable so as to be moved from location to location as desired.
During many manufacturing operations, it is required to cure a workpiece or at least a coating that has been applied to the workpiece. For example, during the construction of an aircraft, sealants and other coatings are oftentimes applied at different times to an article under construction. Prior to continuing with the construction of the article, the sealant or other coating must frequently be cured. While different sealants or other coatings may require different conditions for curing, most materials cure according to some function of time and temperature. As such, workpieces that must be cured can simply remain on the shop floor or elsewhere for some period of time in order to cure. While the times required for various types of sealants and other coatings to cure also vary, it is not uncommon for workpieces to require several days to properly cure prior to continuing with the construction of the article. As will be apparent, the delay introduced into the construction process as a result of the curing cycle is disadvantageous and adds to the overall cost of the article. Moreover, the workpiece oftentimes remains on the shop floor during curing and therefore consumes a portion of the oftentimes limited space available on the shop floor.
The curing process can generally be accelerated by increasing the temperature of the workpiece during the cure process. Cure rooms have therefore been developed to accelerate the cure process. In this regard, cure rooms are generally thermally insulated rooms in which workpieces can be placed during curing. While the workpieces are disposed within the cure room, the temperature within the cure room can be increased and air can be circulated through the cure room in order to accelerate the curing process. While cure rooms are generally successful in reducing the overall time required to cure a workpiece, cure rooms are relatively expensive to construct and may cost $10,000, $15,000 or more. As a result of the cost, not all companies that must cure a workpiece during a manufacturing process have constructed a cure room. Moreover, cure rooms are fixed in position within a manufacturing facility. As such, workpieces that must be cured must be transported to the cure room for curing and thereafter removed from the cure room. While the transportation of some workpieces to and from the cure room is relatively simple, other workpieces may be difficult to transport to a cure room due to the size, shape or weight of the workpiece.
By way of example, the door of an aircraft includes a latch and hinge assembly. During the fabrication process, the latch and hinge assembly is coated with a sealant which must cure prior to continuing the fabrication process. In this regard, the construction process cannot continue until the sealant has cured because of the risk of contamination and disruption to the fey seals.
One common sealant for the latch and hinge assembly has a cure time of 48 hours at room temperature. While the curing of the sealant may be accelerated by placing the door in a cure room, a cure room may not be available or, if available, may be a substantial distance from the location at which the door is being fabricated. As such, the door would be required to be placed upon a transportation device, such as a mobile table, a transportation cart or the like, and moved to the cure room. Since the door is quite heavy and large, it would be difficult to readily move the door to and from the cure room. As such, the door frequently sits on the shop floor during the curing process, such as for 48 hours or so, prior to continuing the fabrication process. Since space on the shop floor is oftentimes in limited supply, the door may prevent other objects from being placed on the shop floor. In addition, the door may actually get in the way or obstruct other operations conducted on the shop floor during the curing process. As such, it would be desirable to accelerate the curing process without requiring that the article under construction be transported to the relatively expensive cure rooms utilized in some manufacturing facilities.
A structure and an associated method are therefore provided for housing a workpiece during curing such that the cure process may be accelerated without requiring the use of a relatively expensive cure room. In this regard, the structure of the present invention may be relatively inexpensive and, in one embodiment, includes a tent that serves as the cure room in which the workpiece is disposed during curing. In addition, the structure of one advantageous embodiment is portable such that the structure may be moved to the location of the workpiece that requires curing in order to prevent the workpiece from having to be transported to a cure room or the like.
According to one aspect of the present invention, a structure is provided for housing a workpiece while at least a portion of the workpiece is curing. The structure includes a cure room, typically formed by a tent, that defines the internal cure chamber in which the workpiece is disposed during curing. The structure may include a heater in communication with the internal cure chamber to heat the workpiece so as to accelerate curing. In addition, the structure may include a fan for circulating air through the internal cure chamber during the curing process.
The tent that preferably defines the internal cure chamber is generally at least partially retractable to permit introduction of the workpiece into the internal cure chamber and the removal of the workpiece therefrom. In this regard, the tent may include a frame and a covering supported by the frame. The covering is typically formed of a relatively flexible cloth or other material and preferably has an inner surface formed of a thermally insulating, heat reflecting, fire resistant material. The frame is adapted to move between a first position which defines an opening to the internal cure chamber to permit the introduction of the workpiece into the internal cure chamber and the removal of the workpiece from the internal cure chamber and a second position in which the opening is closed while the workpiece is cured.
The tent and, more particularly, the frame may include an upstanding wall and a retractable portion extending downwardly and outwardly from the upstanding wall. In order to carry the covering that forms the retractable portion of the tent, the frame may also include at least one and, more typically, a plurality of arms extending outwardly from the upstanding wall. In this regard, the plurality of arms may extend outwardly from a lower portion of the upstanding wall. The plurality of arms are preferably adapted to move between a first position in which the arms extend upwardly along the upstanding wall and a second position in which the plurality of arms are fanned outwardly so as to define different respective angles with the upstanding wall. Thus, by positioning the plurality of arms in the first position, the covering is retracted to permit the workpiece to be introduced into or removed from the internal cure chamber. In order to secure the covering while the frame is in the first position, the tent may also include a strap. By positioning the plurality of arms in the second position, however, the covering is extended downwardly and outwardly from the upstanding wall so as to close the opening and more completely define the internal cure chamber within which the workpiece is disposed.
According to one embodiment, the structure is portable and is therefore capable of being moved between at least first and second locations. As such, the portable structure may include means, such as a plurality of wheels, for moving a cure room, typically defined by the tent, between the first and second locations. As such, the structure may be moved to the location of a workpiece in need of curing in order to avoid transporting the workpiece to a remote cure room or the like.
In operation, the portable structure of the present invention may be moved to the location of a workpiece that is to be cured. At least a portion of the tent is then retracted, such as by being folded in an accordion-like fashion, to provide an opening to the internal cure chamber. The workpiece is then introduced into the internal cure chamber and the tent is repositioned so as to close the opening. Thereafter, the workpiece is cured, such as by heating the internal cure chamber while circulating air therethrough. Once the workpiece has been cured, at least a portion of the tent may again be retracted to define the opening to the internal cure chamber and the workpiece may be removed therefrom through the opening.
Therefore, the structure and method of the present invention permit workpieces to be cured relatively inexpensively and in an accelerated manner. In this regard, the structure is generally formed of a tent that may be at least partially retracted in order to permit the insertion and removal of the workpiece. By utilizing a tent to define the internal cure chamber, the cost of the resulting structure can be substantially reduced relative to a conventional cure room. In addition, the structure of the present invention may be portable so as to be readily positioned proximate a workpiece without requiring that the workpiece be transported.